[PATCH 2/7] GFS2: Fix possible null pointer deref in gfs2_rs_alloc

From: Steven Whitehouse
Date: Wed Nov 07 2012 - 05:42:36 EST


From: Andrew Price <anprice@xxxxxxxxxx>

Despite the return value from kmem_cache_zalloc() being checked, the
error wasn't being returned until after a possible null pointer
dereference. This patch returns the error immediately, allowing the
removal of the error variable.

Signed-off-by: Andrew Price <anprice@xxxxxxxxxx>
Signed-off-by: Steven Whitehouse <swhiteho@xxxxxxxxxx>

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 3cc402c..43d1a20 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -553,7 +553,6 @@ void gfs2_free_clones(struct gfs2_rgrpd *rgd)
*/
int gfs2_rs_alloc(struct gfs2_inode *ip)
{
- int error = 0;
struct gfs2_blkreserv *res;

if (ip->i_res)
@@ -561,7 +560,7 @@ int gfs2_rs_alloc(struct gfs2_inode *ip)

res = kmem_cache_zalloc(gfs2_rsrv_cachep, GFP_NOFS);
if (!res)
- error = -ENOMEM;
+ return -ENOMEM;

RB_CLEAR_NODE(&res->rs_node);

@@ -571,7 +570,7 @@ int gfs2_rs_alloc(struct gfs2_inode *ip)
else
ip->i_res = res;
up_write(&ip->i_rw_mutex);
- return error;
+ return 0;
}

static void dump_rs(struct seq_file *seq, const struct gfs2_blkreserv *rs)
--
1.7.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/